People have made use of metals and other materials for thousands of years. The significance of materials for the development of humankind is evident in the fact that even entire eras, such as the Stone Age, Bronze Age and Iron Age, have been named after the materials people used for tools and utensils.
Although materials have been used throughout the history of humankind, our understanding of the factors behind the typical properties of materials did not begin to develop until the late eighteenth century. Some of these properties arise from the chemical composition of the materials, while some are mainly related to their internal structure and order.
Light, durable steel revolutionized the engineering industry
The development of materials has always been strongly guided by economic factors. The invention of steel production is undoubtedly the most significant materials technology invention for the modern manufacturing industry. Even though the Chinese knew how to produce steel as early as the third century, it was not until the Bessemer converter, patented in 1855, that the cost of steel manufacture was reduced to the same level as that of cast iron. Steel was a lighter and more durable material, and its extensive use enabled the rapid development of machinery and equipment. Steel grades have continuously been improved since that time; they have been made stronger and more durable for the needs of mechanical engineering.
The requirements for engineering industry materials have increased continuously with technological development. In the early twentieth century, practically the only requirement for general structural steel grades was related to their yield strength, which could be improved by increasing the carbon content of the steel. Less emphasis was put on toughness, as steel structures were mainly joined together by means of riveting. When welding became more popular, the weldability of steel grades needed to be improved by reducing their carbon content and improving their toughness by controlling the grain size through alloying.
The research and introduction of new, better materials has always enabled companies to stand out from the competition. A crusher brochure from 1925 by Oy Lokomo Ab, which today is part of Metso, praises the excellence and superiority of the company’s cast steel crusher in comparison with crushers with cast iron structures. The strength and lightness of the new steel structures was seen as a competitive advantage. In 2018, these qualities continue to be important in the development of Metso’s crushers and crushing plants, and materials research continues to be an essential part of product development.
Development guided by energy efficiency and the circular economy
In the engineering industry, strong and durable materials ensure long product life cycles and minimize the environmental effects of equipment during its use. This also creates financial benefits, as equipment wear and tear, as well as damage, cause considerable direct and indirect costs for industry. Indirect costs, such as loss of production during equipment repair or maintenance, can often be higher than the cost of replacing the damaged part.
With the continuous development of technology, better and better materials are needed. The sizes and power capacities of machinery and equipment have increased steadily, and industrial processes have become more demanding. This has led to the development of entirely new types of materials and manufacturing technologies. The efficiency of traditional manufacturing processes has also been improved. Composite and hybrid materials have been developed by combining various groups of materials to create functional structures. Materials can be combined on the nano, micro or macro level, and the ensuing combinations of properties can be tailored to the purpose of use.
Recently, the development of materials and manufacturing technologies has also been guided by energy-efficiency goals and environmental aspects in particular. The environmental effects of materials throughout their life cycles are sought to be minimized as early as the initial stages of the materials development process, and attention is also paid to their recycling or reuse at the end of their life cycles.
The materials with the best and most durable mechanical properties are often also the best in terms of ecologically sustainable development. Improving the strength of materials has made it possible to implement the same functional structure using a smaller amount of material than when using steel. With regard to mobile equipment, lighter structures also mean lower energy consumption (fossil fuels, electricity, etc.). In addition, improved resistance to wear and tear means longer useful lives for structures. In other words, materials technology will play a key role in the circular economy of the future.
Sources: V. Lindroos, M. Sulonen, M. Veistinen: Uudistettu Miekkojan Metallioppi (1986), Oy Lokomo Ab’s product brochure (1925)